1. Field of the Invention
The present invention relates to a service-extensible, completely new “safe service extension platform” which realizes new dimensional safety in which false access by an execute form which implements a digital content providing service can be eliminated without the need to deny that a process which might cause the false access is included in the execute form. Specifically, it relates to a safe service extension platform which is capable of eliminating false access, such as a change of the status of another service, data corruption, and a system down of the platform itself, without the need of inference from the authenticity of the distributor of an execute form, while capable of changing or adding an execute form to achieve service extension, such as a change of a service function/feature or an addition of a new service.
2. Background of the Related Art
As described above, the present invention provides an unprecedented completely new “safe service extension platform”, and therefore it is considerably difficult to give a suitable example thereof that should be given as a conventional art. Initially, three major features unique to the safe service extension platform which is believed to be proposed first by the present invention are described below. A first feature is service extensibility; a second feature is the assurance of safety; and a third feature is achievement of a seamless service extension operation.
The first feature “service extensibility” means that a different user interface is provided for each service, and a change of the user interface or an addition of an unexpected service can be carried out at any time. The second feature “assurance of safety” means that the safety is assured without the need to deny that a process, which might cause false access, is included in an execute form. The third feature “achievement of a seamless service extension operation” means that the operational procedure for service extension can be carried out with the same operational feeling as the operational feeling in utilizing the service.
As described above, the “safe service extension platform” which satisfies all of the three major features cannot be found in conventional art. However, if a conventional art example is required, a push-type service via the Internet which involves the use of a personal computer can be cited as satisfying only the first feature. PointCast(R) of PointCast Network is a push-type service which realizes a news distribution service. The utilization of a plurality of push-type service which involves the use of a personal computer is made possible by installing a browser, which is written in machine language and executed for each service, to the personal computer.
Here, the first feature of the present invention, i.e., the “service extensibility”, is described in conjunction with the push-type service. A new service can be added by installing a browser, which executes a push-type service, to a hard disk of a personal computer. The browser is a computer program written in machine language, and provides a unique and different user interface for each service.
The installation of the browser is conventionally carried out as described below. For example, the browser is installed by firstly activating a file transfer protocol (e.g., ftp) client to download the browser to the client's hard disk, and then activating the downloaded browser. Also, before using a new browser, the browser's settings are operated with a setting menu incorporated in the browser.
The second feature of the present invention, i.e., the “assurance of safety”, is conventionally based merely on speculation, and is not supported by a specific plan. Specifically, the safety of a browser is conventionally based merely on a desire that a malicious third party has not caused the browser to be infected with a computer virus or the like since the browser is obtained through a formal distributor, such as an official home page.
As for the third feature of the present invention, i.e., the “achievement of a seamless service extension operation”, which means a high-level presentation function by a service, in conventional art, a different user interface is realized by changing a browser for each service, resulting in satisfaction of the requirement that different user interfaces are provided for a plurality of services, which is necessary to partially achieve a seamless operation.
Referring to FIG. 18, a conventional service-extensible service platform, which is not safe as described above, is described in detail. As shown in the figure, a conventional service platform PFc includes a service provision source 1610, a delivery system 120, and a terminal device 1630. The service provision source 1610 includes an execute file provider 1111 and a file transfer server 1611. The execute file provider 1111 may be a hard disk drive having an execute file stored therein. The file transfer server 1611 may be a Web server. As will be described later with reference to FIG. 19, the execute file is binary data, typified by a program file which is directly passed to an OS of the terminal device 1630 and executed.
The delivery system 120 transfers an execute file, which is transmitted from the service provision source 1610, to a terminal device 1630 which is spatially and temporally away therefrom.
The terminal device 1630 includes an executor 1133 and an execute file storage device 1132. The executor 1133 activates an execute file stored in the execute file storage device 1132 to execute any process in the terminal device 1630. For example, in the case of activating a file transfer program as an execute file, an execute file for executing a new service, which is received via the delivery system 120, is stored into the execute file storage device 1132. Also, a service can be provided to the user by executing the execute file which executes the service.
FIG. 19 shows by way of example data stored in the execute file storage device 1132 of the service platform PFc. In addition to FE (S1), which is an execute file for service S1, and FE (S2), which is an execute file for service S2, the execute file storage device 1132 has stored therein execute file FE(shell) for a shell for providing a user interface for platform operation, such as activation of an execute file, and FE (file transfer) which is a file transfer program for introducing execute file FE for executing a new service to the terminal device 1630 via the delivery system. Any of these execute files can be implemented in machine language.
FIG. 20 shows software hierarchy in the service platform PFc. As can be seen from the figure, in the service platform PFc, any execute files for executing any services can be newly introduced by activating the file transfer execute file. In this manner, an application layer is composed of execute files immediately above an OS layer composed of an OS (Operating System). As a result, a service-implementing execute file is able to directly reference and control the resource of the OS. Accordingly, the OS is vulnerable to a malicious execute file, and therefore it cannot be said that the service platform PFc is safe.
As for the first feature of the present invention, i.e., the “service extensibility”, it is possible to simply introduce a new service, but conventionally it is not possible to introduce a new service which is seamlessly related to the content viewing as presented by the present invention. That is, the operability in the content viewing and the operability in the introduction of a new service are completely different from each other both in appearance and in procedure. For example, conventionally, in order to install a browser, it is necessary to activate a file transfer protocol client to download the browser to the client's hard disk, and to activate the downloaded browser. Also, before using a new browser, it is required to set the browser by operating a setting menu whose degree of usability is completely different from the degree of usability of a content viewing window of the browser.
Also, conventionally, functionality extension is carried out by using a user interface common to all services. Accordingly, the number of entries of various parameters (an installation destination directory, a user name, etc.) required for installing a program for service extension becomes a logical sum of parameters required for all services. Therefore, when installing a specific service extension program, there is a possibility that the user might be required to enter a basically unnecessary parameter.
In contrast, flexible service extensibility provided by a safe service extension platform according to the present invention realizes service extension with the same operational usability as the content viewing without closing a browser or carrying out a procedure whose usability is completely different from that of the content viewing. That is, it achieves the situation where service extension is carried out as an extension of a normal operation with the same usability as the usability of the content viewing with which the user is most familiar, and without causing the user to carry out operation with the usability specific to the service extension. However, as described above, such extensibility cannot be provided by a conventional service platform, and therefore there is a need for a method for realizing completely new service extension.
As for the second feature of the present invention, i.e., the “assurance of safety”, in fact, it is not so rare that even in a browser obtained through an official distributor, a bug adversely affects the operation of another push-type service, or causes the entire system to go down. Thus, conventionally, it is necessary to assure that the binary data of the browser is valid, i.e., the binary data of the browser does not include a false access process. However, the assurance is based only on a trust-based relationship, and is not intended to ensure that the binary data of the browser includes no false access process.
On the other hand, the safety provided by the safe service extension platform according to the present invention is completely new dimensional safety in which execution of any execute form (corresponding to the browser in the exemplary conventional art) does not adversely affect another service nor cause the entire system to go down. In the conventional art, as a matter of course, such a scheme does not exist, and therefore there is a need for a completely new execution method.
Further, as for the third feature of the present invention, i.e., the “achievement of seamless service extension operation” which executes a high level presentation function, in the conventional art, it is not possible to establish a seamless relationship between service management and content viewing. This is because the service management is carried out with the setting menu of the browser. That is, operation related to the service management cannot be carried out in the content viewing window.
On the other hand, in a high level presentation function by the service provided by the safe service extension platform according to the present invention, content includes service settings. Therefore it has a high level representation equivalent to that of the content, and a server is able to freely set the details of presentation with the same usability of that of the content viewing.
For example, by combining a service setting function with a content using a high level description capability of, for example, filling out a questionnaire and returning it to the server, whereby the user answers the questionnaire for the user's interest, it is made possible to achieve a high level presentation function of setting user preference information for automatically selecting content. Also, the user is able to carry out a high level setting with a simple operation without being aware of when the content ends and the service setting begins.
In the conventional art, as a matter of course, there is no method for executing a high level presentation function by the service presented by the safe service extension platform according to the present invention.
Therefore, an object of the present invention is to provide a safe service extension platform which realizes the above three features.